From 365e1ececb2905f94cc10a5817c5b644a32a3ae2 Mon Sep 17 00:00:00 2001 From: Gaurav Kohli Date: Wed, 5 Oct 2022 22:52:59 -0700 Subject: [PATCH] hv_netvsc: Fix race between VF offering and VF association message from host During vm boot, there might be possibility that vf registration call comes before the vf association from host to vm. And this might break netvsc vf path, To prevent the same block vf registration until vf bind message comes from host. Cc: stable@vger.kernel.org Fixes: 00d7ddba11436 ("hv_netvsc: pair VF based on serial number") Reviewed-by: Haiyang Zhang Signed-off-by: Gaurav Kohli Signed-off-by: David S. Miller --- drivers/net/hyperv/hyperv_net.h | 3 ++- drivers/net/hyperv/netvsc.c | 4 ++++ drivers/net/hyperv/netvsc_drv.c | 19 +++++++++++++++++++ 3 files changed, 25 insertions(+), 1 deletion(-) diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index 25b38a3..dd5919e 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -1051,7 +1051,8 @@ struct net_device_context { u32 vf_alloc; /* Serial number of the VF to team with */ u32 vf_serial; - + /* completion variable to confirm vf association */ + struct completion vf_add; /* Is the current data path through the VF NIC? */ bool data_path_is_vf; diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index f066de0..9352dad 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -1580,6 +1580,10 @@ static void netvsc_send_vf(struct net_device *ndev, net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated; net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial; + + if (net_device_ctx->vf_alloc) + complete(&net_device_ctx->vf_add); + netdev_info(ndev, "VF slot %u %s\n", net_device_ctx->vf_serial, net_device_ctx->vf_alloc ? "added" : "removed"); diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 5f08482..89eb4f1 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -2313,6 +2313,18 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev) } + /* Fallback path to check synthetic vf with + * help of mac addr + */ + list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) { + ndev = hv_get_drvdata(ndev_ctx->device_ctx); + if (ether_addr_equal(vf_netdev->perm_addr, ndev->perm_addr)) { + netdev_notice(vf_netdev, + "falling back to mac addr based matching\n"); + return ndev; + } + } + netdev_notice(vf_netdev, "no netdev found for vf serial:%u\n", serial); return NULL; @@ -2409,6 +2421,11 @@ static int netvsc_vf_changed(struct net_device *vf_netdev, unsigned long event) if (net_device_ctx->data_path_is_vf == vf_is_up) return NOTIFY_OK; + if (vf_is_up && !net_device_ctx->vf_alloc) { + netdev_info(ndev, "Waiting for the VF association from host\n"); + wait_for_completion(&net_device_ctx->vf_add); + } + ret = netvsc_switch_datapath(ndev, vf_is_up); if (ret) { @@ -2440,6 +2457,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev) netvsc_vf_setxdp(vf_netdev, NULL); + reinit_completion(&net_device_ctx->vf_add); netdev_rx_handler_unregister(vf_netdev); netdev_upper_dev_unlink(vf_netdev, ndev); RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL); @@ -2479,6 +2497,7 @@ static int netvsc_probe(struct hv_device *dev, INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change); + init_completion(&net_device_ctx->vf_add); spin_lock_init(&net_device_ctx->lock); INIT_LIST_HEAD(&net_device_ctx->reconfig_events); INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup); -- 2.7.4